package com.yu.designpatterns.singleton;

/**
 * 懒汉式
 * 可以通过synchronized解决，但是效率带来了下降
 */
public class Mgr05 {

    private static Mgr05 INSTANCE;

    private Mgr05(){}

    public static Mgr05 getInstance(){
        if (INSTANCE == null){
            //妄图通过减少同步代码块的方式提高效率，但显然不可行
            synchronized (Mgr05.class){
                try {
                    Thread.sleep(1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                INSTANCE = new Mgr05();
            }
        }
        return INSTANCE;
    }

    public static void main(String[] args) {
        for (int i = 0; i < 100; i++) {
            new Thread(() -> {
                System.out.println(Mgr05.getInstance().hashCode());
            }).start();
        }
    }

}
